.background1{
    background-image: url("./source/background.png");
    background-size: 100% 100%;
    background-repeat: no-repeat;
    position: absolute;
    padding: 0px;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
}

.center {
    margin-left: auto;
    margin-right: auto;
}

* {
    box-sizing: border-box;
    margin: 0; padding: 0;
}

.btn-holder{
    position: absolute ;
    top: 50%;
    left: 50%;
    -webkit-transform: translate(-50%, -50%);
    -moz-transform: translate(-50%, -50%);
    -ms-transform: translate(-50%, -50%);
    -o-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
}

.btn {
    position: relative;
    display: inline-block;
    width: auto; height: auto;
    background-color: transparent;
    border: none;
    cursor: pointer;
    margin: 0 auto;
    min-width: 400px;
}
.btn span {
    position: relative;
    display: inline-block;
    font-size: 30px;
    font-weight: bold;
    letter-spacing: 2px;
    text-transform: uppercase;
    top: 0; left: 0;
    width: 100%;
    padding: 15px 20px;
    transition: 0.3s;
}

::before,
::after {
    position: absolute;
    content: "";
}

/*--- btn-5 ---*/
.btn-5 span {
    color: rgb(28, 31, 30);
    border: 2px solid rgb(249, 211, 27);
    transition: 0.2s;
}

.btn-5 span:hover {
    background-color: rgb(245,245,245);
}

/* 21. hover-border-11 */
.btn.hover-border-11::before,
.btn.hover-border-11::after {
    width: 100%; height: 2px;
    background-color: rgb(54, 56, 55);
    z-index: 2;
    transition: 0.35s;
}
.btn.hover-border-11::before {
    top: 0; right: 0;
}
.btn.hover-border-11::after {
    bottom: 0; left: 0;
}
.btn.hover-border-11:hover::before,
.btn.hover-border-11:hover::after {
    width: 0%;
    transition: 0.2s 0.2s ease-out;
}

.btn.hover-border-11 span::before,
.btn.hover-border-11 span::after {
    width: 2px; height: 100%;
    background-color: rgb(54, 56, 55);
    z-index: 2;
    transition: 0.25s;
}
.btn.hover-border-11 span::before {
    bottom: 0; right: -2px;
}
.btn.hover-border-11 span::after {
    top: 0; left: -2px;
}
.btn.hover-border-11 span:hover::before,
.btn.hover-border-11 span:hover::after {
    height: 0%;
}

#group{
    display: flex;
}